Conveyor drive roller

ABSTRACT

There is disclosed a conveyor drive roller of the type which may be used for example for supporting and driving a conveyor medium. The conveyor drive roller has a hollow drum which defines a cylindrically shaped rotatable supporting surface, and an internal surface. The hollow drum is rotatably connected to a first and a second support structure. An internal gear assembly is disposed inside of the hollow drum and operably connected to the internal surface of the hollow drum. The second support structure is adapted to permit a rotor of a motor located outside of the hollow drum to releasably couple to the internal gear assembly through the second support structure, so that when the rotor is coupled to the internal gear assembly, through the second support structure, rotation of the rotor is transmitted by the internal gear assembly to the hollow drum to cause rotation of the hollow drum about the first and second support structures.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Canadian Application No. 2619247,filed Feb. 5, 2008, titled “CONVEYOR DRIVE ROLLER”, the contents ofwhich are incorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates generally to conveyor roller systems forconveying or moving objects from one place to another. Conveyor systemsgenerally employ a series of rollers on which a continuous belt or otherconveyor medium travels. Some of the rollers in such a system act asdrive rollers and are rotated to move the belt. The present inventionrelates, in particular, to conveyor drive rollers driven by electricmotors for use in such conveyor belt systems.

BACKGROUND OF THE INVENTION

A variety of conveyor roller systems have been designed and utilized. Alarge variety of known conveyor systems comprise a continuous belt orconveyor medium which travels over a series of conveyor rollers.

Early conveyor roller systems utilized at least one conveyor driveroller which was driven by an electric motor positioned outside of, andconnected to, the conveyor drive roller typically via a chain or rubberbelt, and often with an external gear assembly positioned between themotor and the conveyor roller. The conveyor drive roller therebytranslated the rotational movement of the electric motor to linearmovement of the conveyor medium. The main disadvantage of these earlydesigns, which are still utilized today, is that they take up a lot ofspace. However, the exposed moving parts also pose a hazard to workers,especially the external gear assembly and chain from the external gearassembly to the conveyor roller, which output high levels of torque, ascompared to the motor on its own. The exposed moving parts also pick updebris which damages the conveyor roller system.

In later conveyor roller systems, the electric motor was arranged withinthe conveyor drive roller to provide a more compact conveyor rollersystem as taught, for example, in U.S. Pat. No. 1,725,740 to Schulte.

An example of an even more advanced conveyor drive roller is disclosedin U.S. Pat. No. 5,088,596 to Agnoff, which teaches a motorized conveyordrive roller mounted in a conveyer frame to support and propel articlesfrom one end of the conveyor path towards the opposite end. The Agnoffconveyer drive roller includes a roller tube rotatably mounted in theconveyor frame and drive means contained inside the roller tube fordriving the roller tube. The drive means includes a motor, a gearreducer assembly operatively connected to the motor, and a drive memberconnected to the outward shaft of the speed reducer for engaging androtating the roller tube.

Conveyor roller systems having conveyor drive rollers which are drivenby motor and gear combinations, contained entirely within the conveyordrive roller itself, are of particular utility in many applications. Theinternal motor and gear system makes for a compact, space savinginstallation. Furthermore, the linear arrangement of the motor andgearing within the conveyor drive roller means that the transmission ofpower from the motor to the roller is carried out more directlyresulting in higher levels of efficiency than is possible inconventional conveyor roller systems where the motor is locatedexternally to the conveyor drive roller, especially where the axis ofrotation of the rotor is at a 90° angle to the axis of rotation of theroller. The internal motor and gear combination also largely eliminatesthe risk of accident caused by contact with employees. Furthermore, iteliminates contamination of the motor/gear drive from dust and debris inthe environment in which it is running, thereby greatly reducingmaintenance, and the likelihood of failure, all of which results in lessdown time for the conveyor system.

All of these factors make the use of such conveyor drive rollersparticularly useful and desirable. However, they also havedisadvantages.

One such disadvantage is that while the likelihood of failure of such aconveyor drive roller is decreased, when it does fail servicing is verydifficult and expensive, since it requires the shutting down of theconveyor roller system, removal of the entire defective conveyor driveroller (which is quite heavy since it contains the motor and gearing),which is then sent elsewhere for servicing. The conveyor roller systemremains shut down until a new or repaired conveyor drive roller isinstalled in the conveyor system in place of the removed, defective one.Since conveyor drive rollers of this type (i.e. having the motor andgearing within them) are fairly expensive, companies that employconveyor systems which utilize them typically do not stock spareconveyor drive rollers. This means that the conveyor system remainsshutdown until the defective conveyor drive roller is repaired andreinstalled.

Therefore, there is a need for improvement in the design of conveyordrive rollers.

SUMMARY OF THE INVENTION

Although mechanical breakdown of conveyor drive motors in which themotor and gear mechanism is entirely contained within the conveyor driveroller itself is far less likely than traditional conveyor driverollers, they do still break down. It is typically the motor which failsin such units. However, accessing and repairing the motor when it islocated inside the conveyor drive roller requires special tooling andsignificant time, and expense as described above.

Therefore, what is desired is a conveyor drive roller which has theadvantages of the prior art conveyor drive rollers with the internalmotor and gear combination, but which results in less down time when afailure in the motor occurs, by virtue of the motor being outside of thedrive roller where it can be more easily accessed, repaired, and/orreplaced.

Accordingly, the present invention provides a conveyor drive roller inwhich the gear assembly is contained inside a sealed conveyor driveroller and protected from the environment, while the electric motor islocated outside of the conveyor drive roller and connected to theinternal gear assembly. This facilitates preventative servicing andmaintenance, and simplifies replacement and repair of the motor if itfails.

Furthermore, workers near the conveyor drive roller are protected fromaccidentally coming into contact with the moving parts of the gearassembly (since it is located within the conveyor drive roller), whichmay cause physical damage or catch any loose clothing into the system,as may otherwise occur in a conventional conveyor drive roller, in whichthe gear reducer, motor, couplings, and belts or chains are exposedoutside of the roller.

Another advantage is that with the internal gear assembly and externalmotor, the conveyor drive roller of the conveyor drive roller of thepresent invention is more compact than the conventional drive roller, inwhich the gear reducer, motor, couplings, and belts or chains areoutside of the roller.

Yet another advantage of the conveyor drive roller of the presentinvention is that by locating the motor outside of the conveyor driveroller the motor does not need to be sold with the conveyor driveroller. This allows the user to purchase an economical spare motor, fromany supplier, to be kept in stock in case it becomes needed to replace adefective motor. The replacement of the motor in this invention is muchfaster and easier than replacing the motor in a drive roller where themotor is located within the roller. This arrangement also allows theuser to select from a range of standard motors when building theconveyor system, or to upgrade or change an installed conveyor system toperform in a different application or environment.

Yet another advantage is that by coupling the external motor directly tothe internal gear assembly and aligning the axis of rotation of therotor parallel with the axis of rotation of the conveyor drive rollerthe transfer of power from motor to roller is very efficient. Such anarrangement results in energy cost savings relative to conventionalconveyor drive rollers, in which the axis of rotation of the rotor istypically at a 90° angle to the axis of rotation of the roller, forspace conservation.

Therefore, in accordance with one aspect of the present invention thereis provided a conveyor drive roller comprising:

a hollow drum defining a rotatable supporting surface having acylindrical shape and an internal surface, said hollow drum beingrotatably connected to a first and a second support structure;

an internal gear assembly disposed inside said hollow drum and operablyconnected to said internal surface of said hollow drum;

said second support structure being adapted to permit a rotor of a motorlocated outside of said hollow drum to releasably couple to saidinternal gear assembly through said second support structure;

wherein when said rotor is coupled to said internal gear assembly,through said second support structure, rotation of said rotor istransmitted by said internal gear assembly to said hollow drum to causerotation of said hollow drum about said first and second supportstructures.

In accordance with another aspect of the present invention there isprovided a conveyor drive roller comprising:

a hollow drum defining a rotatable supporting surface having acylindrical shape, said hollow drum being rotatably connected to a firstand a second support structure;

an internal gear assembly disposed inside said hollow drum and operablyengaging said hollow drum;

a rotatable element rotatably carried by said second support structure,said rotatable element having two ends, one of said ends operablyengaging said internal gear assembly, and the other of said ends beingadapted to couple to a rotor of a motor;

wherein when said rotor is coupled to said other end of said rotatableelement, rotation of said rotor is transmitted by said rotatable elementand said internal gear assembly to said hollow drum to cause rotation ofsaid hollow drum about said first and second support structures.

In accordance with yet another aspect of the present invention there isprovided a conveyor drive roller for supporting and driving a conveyormedium, said conveyor drive roller comprising:

a hollow drum defining a rotatable supporting surface having acylindrical shape, said hollow drum being rotatably connected to a firstand a second support structure, said second support structure having achannel therethrough, and an exterior end adapted to mount a motor witha rotor;

an internal gear assembly disposed inside the hollow drum;

said internal gear assembly being operably connected to said hollowdrum;

said internal gear assembly also being adapted to operably couple tosaid rotor;

wherein when said motor is mounted to said exterior end and saidinternal gear assembly is operably coupled to said rotor, through saidhollow channel, rotation of said rotor is transmitted by said internalgear assembly to said hollow drum to cause rotation of said hollow drumabout said first and second support structures.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the preferred embodiments of the presentinvention with reference, by way of example only, to the followingdrawings in which:

FIG. 1 is a full cross-sectional view of a conveyor drive rolleraccording to an embodiment of the present invention;

FIG. 2 is partial view of a cross-section of one end of the conveyordrive roller of FIG. 1;

FIG. 3 is a partial view of a cross-section of the other end of theconveyor drive roller of FIG. 1, with parts omitted for clarity;

FIG. 4 is a partial view of a cross-section of the other end of theconveyor drive roller of FIG. 3 with omitted parts present and a motormounted thereto;

FIG. 5 is a partial view of a cross-section of a portion of the conveyordrive roller of FIG. 1 showing the internal gear assembly; and

FIG. 6 is a full cross-sectional view of a conveyor drive rolleraccording to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is described in more detail with reference toexemplary embodiments thereof as shown in the appended drawings. Whilethe present invention is described below including preferredembodiments, it should be understood that the present invention is notlimited thereto. Those of ordinary skill in the art having access to theteachings herein will recognize additional implementations,modifications, and embodiments which are within the scope of the presentinvention as disclosed and claimed herein. In the figures, like elementsare given like reference numbers. For the purposes of clarity, not everycomponent is labelled in every figure, nor is every component of eachembodiment of the invention shown where illustration is not necessary toallow those of ordinary skill in the art to understand the invention.

A conveyor drive roller 10 according to the present invention isdisclosed in FIG. 1. The conveyor drive roller 10 consists of acylindrical drum 12, having ends 14 and 16. Stationary shafts 18 and 20extend through respective ends 14, 16. The stationary shafts 18 and 20can be mounted on any suitable support or frame work (not shown) andsecured on for example blocks or clamps (not shown), all of which isknown and requires no detailed description.

The conveyor media (not shown) typically a belt or flexible strip of anysuitable material, or a matrix of chain links, or the like runs aroundthe outer surface 22 of the drum 12 and is driven by drum 12, whichrotates about shafts 18 and 20. Such conveyor media may also run aroundother conveyor drive rollers (not shown), and may run over intermediatesupport rollers (not shown). Furthermore the outer surface 22 caninclude any variety of means to increase the co-efficient of frictionbetween the outer surface 22 and the conveyor medium such as for exampleby knurling or machining a spiral at each end toward the center or bycovering the outer surface 22 with rubber or the like.

As shown in FIG. 2 in an enlarged view of end 14, an annular end flange24, is press fit into the drive drum 12. The end flange 24 has a hole inthe middle, which defines a lip 26 facing outside of the drive drum 12.A bearing cassette 28 is fit within the hole in the end flange 24. Thecassette has a collar 32 for securement to the lip 26 of the end flange24 by fasteners 30, such as socket head caps as shown. Two spaced apartbearings 34 are positioned within the cassette 28 about the shaft 18.The exterior portion 17 of shaft 18 is preferably mountable on, andsecurable to, a suitable support or frame work (not shown). For example,the exterior portion 17 of shaft 18 may have a generally cylindricalprofile with two flat sections at opposite sides, for locking in aU-shaped member, or clamp on the frame. Furthermore, although twobearings 34 are preferred in order to reduce the amount of play on theshaft 18, as is well known in the art, it is contemplated that onebearing positioned in the cassette 28 will also work. It is alsocontemplated that the end flange 24 and cassette 28 may be provided as aunitary construction. What is important is that drum 12 is rotatablyconnected to shaft 18 at end 14.

FIG. 3 is an enlarged view of end 16, with parts omitted to more clearlyshow how drum 12 is rotatably connected to shaft 20. As shown, asecuring ring 36 is press fit into the drive drum 12. End flange 38 issecured to the securing ring 36 by fasteners 40, such as socket headcaps as shown, with a gasket 37 positioned between the securing ring 36and the end flange 38. The end flange 38 is sized and shaped with a holeto accommodate bearing 42, bearing race and oil seal 46 about shaft 20.Preferably, shaft 20 has a hollow interior and comprises threecomponents, namely a C-flange motor mount 48, an extender 50, and aninternal gear assembly mount 52. C-flange motor mount 48 is preferablysized and shaped for mounting a motor 54 according to the NationalElectrical Manufacturers Association (NEMA) standards. The threecomponents are secured together with fasteners 53 in a known manner.However, it will be appreciated that the shaft 20 may comprise more orfewer components. What is important is that drum 12 is rotatablyconnected to shaft 20 at end 16, and be capable of operably mounting anexternal motor 54. Shaft 20 is preferably mountable on, and securableto, a suitable support or frame work (not shown) at extender 50. Forexample, the exterior of extender 50 may have a generally cylindricalprofile with two flat sections at opposite sides, for locking in aU-shaped member, or clamp on the frame.

As can now be understood shafts 18 and 20 form a support structure aboutwhich drum 12 can rotate, when mounted on a suitable frame (not shown).

FIG. 4 is an enlarged view of end 16, with parts omitted to more clearlyshow how motor 54 is coupled to the internal gear assembly (omitted fromthis view). As shown, motor 54 is a conventional electric motor, and istherefore not described in any more detail. Preferably the motor issized and shaped in accordance with the NEMA standards, which will fitan appropriately sized and shaped C-flange motor mount 48 of shaft 20.The motor 54 is mounted to the C-flange motor mount 48 by fasteners 56,such as socket head caps as shown. The rotor 58 of the mounted motor 54extends through bearings into the hollow of shaft 20. One half of aLovejoy® coupling (i.e. LO 95) 62 is secured to the operative end of therotor 58. The other half of the Lovejoy® coupling 64 is secured (i.e. bypress fitting) to one end of a rotational element 66. The other end ofthe rotational element 66 has a pinion 68. A spider insert 70 ispositioned between the two halves of the Lovejoy® coupling. As is knownin the art the spider 70 has vibration dampening properties andmisalignment correction capabilities, etc. While the preferred mode ofcoupling the motor 54 to the internal gear assembly is described asusing a Lovejoy® coupling, it will be understood that many other typesof coupling are possible and will be known to persons skilled in theart, such as a tongue and groove couplings. What is important is thatthe mode of coupling will permit the motor 54 to easily decouple fromthe rotational element 60, such as for example by simply sliding themotor 54 away from the C-flange motor mount 48. This permits easy accessto the motor 54 for maintenance, repair and replacement, withoutnecessitating the removal of the entire conveyor drive roller 10 fromthe conveyor frame (not shown). Thus, repair or replacement of a faultymotor 54 will typically result in only a brief down time of theconveyor. Furthermore, with the internal gear assembly being providedinside the drum 12, the conveyor drive roller 10 according to thepresent invention takes up less space as compared to a conventionalconveyor drive roller (not shown) in which the gear reducer, motor, andcouplings and belts or chains are all located outside of theconventional conveyor drive roller. Moreover, providing the internalgear assembly inside the drum 12 removes the possibility of debris(which can cause damage to the conventional conveyor drive roller), andespecially worker's clothing being caught (which is a hazard), both ofwhich possibilities are issues with conventional conveyor drive rollersin which the moving parts of the gear reducer, motor, couplings andbelts or chains being exposed. The torque from the gear reducer andbelts or chains is much higher, and more dangerous to nearby workers,than the torque from the motor itself.

With continued reference to FIG. 4, the rotational element 66 is shownpreferably of unitary construction, and being sized and shaped to passthrough the hollow of shaft 20 to extend past the gear assembly mount 52inside the drum 12. Also shown are a bearing 72 and oil seal 74, betweenthe gear assembly mount 52 and the mid portion of the rotational element66. What is important is that the rotational element 66 be capable oftransferring the torque from the rotor 58 of the motor 54 to theinternal gear assembly (not shown in this view) through the hollow ofshaft 20.

FIG. 5 is an enlarged view of a portion of the conveyor drive roller 10containing the internal gear assembly according to a preferredembodiment of the present invention. As shown, a gear housing 76 issecured to the gear assembly mount 52 with fasteners 78 such as the onesocket head cap which can be seen in this view. The gear housing 76 issized and shaped to hold a bearing 80 about the rotational element 66adjacent the pinion 68, and a drive gear 82 in engaging relation withthe pinion 68. The drive gear 82 preferably comprises an output gear 84with a shaft 86 extending therefrom, a sleeve 88 press fit about aportion of the shaft 86, and a gear 90 press fit about a portion of thesleeve 88. The drive gear 82 is rotatable in the gear housing 76 bybearing 92 and needle bearing 94. A spacer 96 is shown about the sleeve94 between the gear 90 and the bearing 92 to prevent the gear 90 fromrubbing against the gear housing 76. As can now be understood, the teethof the pinion 68 mesh with the teeth of the gear 90 so that rotation ofthe rotational element 66 causes rotation of the drive gear 82 withinthe gear housing 76.

The teeth of the output gear 84 mesh with interior ring gear 98 on plate100, which is secured to mid flange 102, which in turn is sealinglysecured to a mounting ring 106 which is press fit inside the drum 12. Aswill be appreciated, the securement of the plate 100 to mid flange 102,and the mid flange 102 to the mounting ring 106 may be by fasteners 104.It is also contemplated that mounting ring 106, plate 100, and midflange 102 may be provided as a unitary construction, or a two, or morepiece construction. What is important is that rotational movement ofoutput gear 84 is translated into a rotational movement of drum 12.Furthermore, it is preferable to extend a stabilizing shaft 108 from thegear housing 76, along the axis of rotation of the drum 12 to a bearing110 held in mid flange 102 to help prevent the gear assembly fromwobbling inside the drum 12 during use.

In a preferred embodiment of the present invention the internal gearassembly is configured to reduce the rate of rotational movement of thedrum 12 relative to the rate of rotational movement of the rotor 58 bythe motor 54. However, it will be appreciated that the internal gearassembly can be configured to also increase the rotational movement ofthe drum 12 relative to the rotational movement of the rotor 58 of motor54. The use of gears and gear ratios to be used will be understood bythose skilled in the art; and therefore, requires no detaileddescription.

A compartment 112 containing the gear assembly is formed between the midflange 102 and end flange 38. Preferably, the compartment 112 is partlyfilled with gear oil, ensuring proper lubrication and cooling duringoperation of the conveyor drive roller 10.

In use, conveyor drive roller 10 is mounted to a frame (not shown) byshafts 18 and 20, in a manner which prevents shafts 18, 20 fromrotating. When energized by operation of a suitable start switch (notshown) motor 54, spins rotor 58, which is coupled to rotational element66 by the Lovejoy® coupling 60, 62, 64. Rotational element 66 has at itsother end a pinion 68 which meshes with gear 90, at one end of drivegear 82, causing the output gear 84, at the other end of drive gear 82to rotate in gear housing 76. Output gear 84 meshes with ring gear 98which causes the drum 12 to rotate about stationary shafts 18 and 20,since output gear 84 is linked to the inside of the drum 12 by virtue ofthe securement to mid plate 102 and ultimately to the inside of the drum12 via mounting ring 106. Rotation of drum 12 in turn causes movement ofthe conveyor media (not shown) carried on drum 12, which will move anyproduct on the conveyor along its desired path.

The inline mounting of the motor 54 to the conveyor drive roller 10according to the present invention, wherein the motor 54 is directlycoupled to the internal gear assembly, and the rotor's 58 axis ofrotation is parallel with the conveyor drive roller's 10 axis ofrotation results in significant energy savings compared to conventionalconveyor drive rollers with external gear reducers, motors, couplings,and belts or chains, because the transfer of power is much moreefficient.

While reference has been made to various preferred embodiments of theinvention other variations are comprehended by the broad scope of theappended claims. Some of these have been discussed in detail in thisspecification and others will be apparent to those skilled in the art.

For example, according to another embodiment of the present invention,it is contemplated that to take up less space, the motor 54 may bemounted underneath the drum 12. Accordingly, the conveyor drive roller10 may be provided with a shaft 20 without the C-flange motor mount 48,and in place of the Lovejoy® coupler 64, the end of the rotationalelement 66 may be provided with a pulley 114. Thus, as shown by way ofexample in FIG. 6, the motor 54 is coupled to the rotational element 66by a power transmission belt 116.

All such variations and alterations are comprehended by thisspecification are intended to be covered, without limitation.

The invention claimed is:
 1. A conveyor drive roller for supporting anddriving a conveyor medium, said conveyor drive roller comprising: ahollow drum defining a rotatable supporting surface having a cylindricalshape, said hollow drum being rotatably connected to a first and asecond support structure, said second support structure having apassageway therethrough, and an exterior end comprising a C-flange motormount sized and shaped to releasably mount a corresponding externalmotor with a rotor; an internal gear assembly disposed inside saidhollow drum; said internal gear assembly being operably connected tosaid hollow drum; said internal gear assembly also being adapted toreleasably couple to said rotor; wherein when said motor is mounted tosaid C-flange motor mount and said internal gear assembly is releasablycoupled to said rotor, through said passageway, rotation of said rotoris transmitted by said internal gear assembly to said hollow drum tocause rotation of said hollow drum about said first and second supportstructures.
 2. A conveyor drive roller as claimed in claim 1, furthercomprising a rotatable element at least partly supported by, and passingthrough said passageway in said second support structure, said rotatableelement having a first end operably engaging said internal gearassembly, and a second end adapted to couple to said rotor of saidmotor.
 3. A conveyor drive roller as claimed in claim 2, wherein saidcoupling between said rotor and said other end of said rotatable elementis a tongue and groove coupling.
 4. A conveyor drive roller as claimedin claim 2, wherein said second end of said rotatable element has acoupling head for coupling with a corresponding coupling head on saidrotor, each coupling head being formed with jaws configured to intermeshwith an intermediate spider having lugs fitting between the jaws.
 5. Aconveyor drive roller as claimed in claim 1, wherein said motor conformsto National Electrical Manufacturers Association (NEMA) standards.
 6. Aconveyor drive roller as claimed in claim 1, wherein said second supportstructure has an internal end, and said internal gear assembly ismounted thereto.
 7. A conveyor drive roller as claimed in claim 6,further comprising an internal gear assembly mount.
 8. A conveyor driveroller as claimed in claim 1, wherein said second support structurefurther comprises an extender.
 9. A conveyor drive roller comprising: ahollow drum defining a rotatable supporting surface having a cylindricalshape and an internal surface, said hollow drum being rotatablyconnected to a first and a second support structure; an internal gearassembly disposed inside said hollow drum and operably connected to saidinternal surface of said hollow drum; and a rotatable element rotatablycarried by said second support structure, said rotatable element havinga first end operably engaging said internal gear assembly, and a secondend adapted to releasably couple to a rotor of an external motor; saidsecond support structure having an external end comprising a C-flangemotor mount for releasably mounting said motor with the rotor releasablycoupled to said second end of said rotatable element; said second end ofsaid rotatable element having a coupling head for coupling to acorresponding coupling head on said rotor, each coupling head beingformed with jaws configured to intermesh with an intermediate spiderhaving lugs fitting between the jaws; wherein when said rotor is coupledto said rotatable element, rotation of said rotor is transmitted to saidhollow drum, via said internal gear assembly, to cause rotation of saidhollow drum about said first and second support structures.